NAME

       lc_mmapfile - map or unmap files or devices into memory

LIBRARY

       Librecast library (liblibrecast, -llibrecast)

SYNOPSIS

       #include <librecast/sync.h>

       void *lc_mmapfile(const char *pathname, size_t *len, int prot, int flags,
                         off_t offset, struct stat *sb);

       Compile and link with -llibrecast.

DESCRIPTION

       The  lc_mmapfile() function is a convenience wrapper for mmap(2) which open(2)s and maps a
       file in a single call. See mmap(2) for a full description.

       If prot has the PROT_WRITE flag set, pathname is open(2)'ed with the  O_RDWR  and  O_CREAT
       flags  set  (the  file is created and opened read-write), otherwise it is opened O_RDONLY.
       The mode for the  created  file  can  be  set  by  setting  st_mode  in  sb  when  calling
       lc_mmapfile().

       If len points to a value greater than zero, ftruncate(2) is called to truncate the file to
       the specified length. Otherwise, the variable len points to is set  to  the  size  of  the
       file.

       When done, the file can be unmapped and the memory freed by calling munmap(3).

RETURN VALUE

       On  success,  lc_mmapfile()  returns  a  pointer  to  the mapped area. On error, the value
       MAP_FAILED (that is, (void*)-1 ) is returned, and errno is set to indicate the error.

ERRORS

       ENODATA
              File is zero length.

       See also open(2), mmap(2), fstat(2), and ftruncate(2).

SEE ALSO

       mmap(2), msync(2), munmap(2), open(2), fstat(2), ftruncate(2)